Winding mechanism

A winding mechanism for an architectural covering, such as a blind or shade, said mechanism including a fixed, stationary shaft having an axis, an inner sleeve mounted for rotation relative to said stationary shaft about said axis, a one way clutch permitting relative rotation between said inner sleeve and said shaft about said axis in one rotation sense, but preventing rotation relative in the opposite sense, an outer sleeve mounted for rotation relative to said inner sleeve, said outer sleeve having a substantially cylindrical inner wall, and said inner sleeve having a substantially cylindrical outer surface, radially spaced from and extending within said inner wall by a given radial distance, a drive member rotatable relative to said stationary shaft, and a cord secured at a first end to said drive member, said cord being helically wrapped about said outer surface of said inner sleeve, within the outer sleeve, a second end of said cord being secured to said outer sleeve, the arrangement being such that the weight of the blind or shade which in use tends to rotate the outer sleeve in said one rotational sense, thereby causing the cord to tighten on the outer surface of the inner sleeve, and locking said outer sleeve to said inner sleeve, and preventing rotation of said outer sleeve in said opposite rotational sense.